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New Zealand earthquake has lessons for urban centres

The 6.3 magnitude earthquake that struck Christchurch, New Zealand on Feb. 22 demonstrates the vulnerability of urban centres with important lessons for the United States, says an American engineering expert.

ITHACA, N.Y.

The 6.3 magnitude earthquake that struck Christchurch, New Zealand on Feb. 22 demonstrates the vulnerability of urban centres with important lessons for the United States, says an American engineering expert.

“The earthquake was actually an aftershock associated with the 7.1 magnitude Darfield earthquake that occurred about 15 kilometres west of Christchurch on Sept. 4, 2010,” said Thomas D. O’Rourke, an expert on the impact of earthquakes on infrastructure and professor of civil and environmental engineering at Cornell University.

“Since then, aftershocks have been occurring on the Greendale Fault, the causative fault, and progressing toward the Christchurch central business district.”

The relatively shallow depth of the earthquake below the city shows that “even five to 10 seconds of strong shaking” can have devastating effects in an urban centre.

“Some reasons for the serious damage are the many unreinforced masonry buildings in Christchurch and the occurrence of soil liquefaction” said O’Rourke.